European Patent No. 121,828 published on Nov. 19, 1987 (priorities: 4/12/83 and 8/30/83) discloses certain hydroxy compounds of formula ##STR3## wherein each of symbols R.sup.1 and R.sup.2 represents a methyl radical or wherein R.sup.1 stands for an ethyl radical and R.sup.2 represents a methyl radical or a hydrogen atom.
One of the objects of the cited patent is the utilization as fragrance ingredients of the said hydroxy compounds, especially in their trans configuration or in the form of mixtures containing proportions higher than 50% by weight of the trans isomer together with minor amounts of the corresponding cis derivative.
Amongst the compounds defined by generic formula (I), 1-(2,2,3,6-tetramethyl-1-cyclohexyl)-3-hexanol presents a particular interest due to its ambery and animal odorous note which is both elegant and powerful.
The prior art discloses two processes for its preparation [see above cited patent]. One uses 2,3,6-trimethyl-cyclohex-5-en-1-one as starting material according to the following reaction scheme: ##STR4##
The second process uses certain ester derivatives of .alpha.-cyclogeranic acid and can be illustrated by the following reaction scheme: ##STR5##
As it becomes apparent from the above given schemes, one of the critical intermediates in this process is 2,2,3,6-tetramethyl-cyclohexane-carbaldehyde.
This invention offers a novel and technically satisfactory solution to the problem of preparing the said aldehyde, namely the compound defined by the following formula ##STR6## wherein the wavy line defines a C--C bond of cis or trans configuration, and wherein the two methyl substituents in position 3 and 6 possess the trans configuration.